A Florida judge ordered 40 prospective jurors who passed an initial vetting to return to court on Wednesday to start the second and final round of questioning in the murder trial of neighborhood watch volunteer George Zimmerman.

Zimmerman's defense team estimates the second round will be completed in two days, with opening statements as soon as Monday, followed by witness testimony.

Zimmerman, 29, is accused of racially profiling Trayvon Martin, an unarmed black teenager and guest of a homeowner at a gated community in Sanford, and shooting him during a struggle in February 2012.

The case drew international media attention and nationwide protests after police initially let Zimmerman, a light-skinned Hispanic, walk free based on his claim of self-defense.

George Zimmerman stands as the judge leaves the courtroom as jury selection continues in his second-degree murder trial in Sanford, Florida, June 18, 2013. Zimmerman is accused of the fatal shooting of unarmed black teenager Trayvon Martin in February, 2012. (Joe Burbank/Pool/Reuters) (POOL)

Prosecutors and defense lawyers on June 10 began questioning prospective jurors about what they know about the case from the intense news coverage it generated and opinions they might have formed. The prospective jurors were questioned individually to avoid spreading details and viewpoints about the case.

In the second round, the potential jurors will be questioned as a group on issues that could include race, guns and self-defense.

Six jurors and at least four alternates will be chosen to hear the case.